named-space

<xs:simpleType name="named-space">
  <xs:restriction base="xs:string">
    <xs:enumeration value="veryverythinmathspace"/>
    <xs:enumeration value="verythinmathspace"/>
    <xs:enumeration value="thinmathspace"/>
    <xs:enumeration value="mediummathspace"/>
    <xs:enumeration value="thickmathspace"/>
    <xs:enumeration value="verythickmathspace"/>
    <xs:enumeration value="veryverythickmathspace"/>
  </xs:restriction>
</xs:simpleType>